Bob Sawyer wrote:
"I`m thinking the corrosion wouldn`t be a problem;--"

I think Bob is right.

Paint doesn`t help much, but it doesn`t hurt. You never see a new
microwave dish that isn`t painted before shipment, mostly for
appearance, but the paint inhibits corrosion too.

Aluminum spontaneously and rapidly forms oxide on its surface from
contact with air. Surface oxide is a barrier to further oxidation. A
painted dish is already oxidized before it is painted.

Rapid oxidation was one of the problems with aluminum house wiring.
Sound electrical connections were hard to make and keep. Depending on
the alloy, aluminum oxide (alumina) has such a high resistance that it
is used as an insulator at high temperatures. Fretting corrosion is
caused by interaction of aluminum with other metals and creates
corrosion problems (extreme resistance) at junctions.

Aluminum is a satisfactory material for antennas. Witness the millions
of outdoor TV antennas. High resistance of the thin oxide coating is not
incapacitating.

Best regards, Richard Harrison, KB5WZI